Micro-channel pulsating heat pipe

Abstract

A heat pipe device and a corresponding method in which micro-channel embedded pulsating heat pipes are incorporated into a substrate. A volume of fluid in a vacuum is introduced into a micro-channel which will become slugs of liquid. Heating of the contents of the micro-channel at an evaporator region (heat source) will cause vaporization within the micro-channel and cooling at a heat sink will cause condensation within the micro-channel, acting to both drive fluid flow within the micro-channel and efficiently transfer heat. Such devices could be used in a number of different configurations, including one as a stacked set of micro-channel embedded substrates.

What is claimed is: 
     
       1. A micro-channel embedded heat pipe comprising:
 a first sheet having a first serpentine trace pattern; 
 a second sheet bonded onto said first sheet, said second sheet having a second serpentine trace pattern substantially matching said first serpentine trace pattern such that when said first sheet and said second sheet are bonded together to form a bonded sheet, a wire-free serpentine micro-channel is formed in said bonded sheet; and 
 at least one fill tube on at least one edge of the bonded sheet, allowing introduction of a fluid into said wire-free serpentine micro-channel; 
 wherein said wire-free serpentine micro-channel has a first end region having an evaporator region and has an opposed second end region having a condenser region. 
 
     
     
       2. The micro-channel embedded heat pipe of  claim 1 , further including:
 a liquid, contained within said wire-free serpentine micro-channel and partially filling said wire-free serpentine micro-channel; and 
 said wire-free serpentine micro-channel having a portion that is evacuated to at least a partial vacuum. 
 
     
     
       3. The micro-channel embedded heat pipe of  claim 1 , wherein said wire-free serpentine micro-channel has said evaporator region and said condenser region each including a respective plurality of bends of said wire-free serpentine micro-channel. 
     
     
       4. The micro-channel embedded heat pipe of  claim 1 , further comprising a working fluid introduced into said wire-free serpentine micro-channel, wherein said wire-free serpentine micro-channel spanning between said condenser region and said evaporator region is sealed after partially filling said wire-free serpentine micro-channel with said working fluid wherein no active fluid driver is in fluid communication with said working fluid. 
     
     
       5. A micro-channel embedded heat pipe comprising:
 a planar substrate; 
 a wire-free serpentine micro-channel embedded within said planar substrate; 
 a working fluid that partially fills said wire-free serpentine micro-channel; 
 at least one evaporation region, on said planar substrate, the at least one evaporation region including a plurality of bends of said wire-free serpentine micro-channel; and 
 at least one condensation region on said planar substrate. 
 
     
     
       6. The micro-channel embedded heat pipe of  claim 5 , further comprising:
 a plurality of stacked planar substrates, including said planar substrate, each of said planar substrates having a respective serpentine micro-channel embedded therewithin; 
 said at least one evaporation region being included on said plurality of stacked planar substrates; and 
 said at least one condensation region being included on said plurality of stacked planar substrates. 
 
     
     
       7. The micro-channel embedded heat pump of  claim 5 , wherein at least one evaporation transfer region includes a plurality of evaporation thermal transfer regions. 
     
     
       8. The micro-channel embedded heat pump of  claim 5 , wherein at least one condensation transfer region includes a plurality of condensation thermal transfer regions. 
     
     
       9. The micro-channel embedded heat pump of  claim 5 , wherein said planar substrate is incorporated into a structural element. 
     
     
       10. The micro-channel embedded heat pump of  claim 5 , wherein the serpentine channels may vary in diameter size allowing the regulation of flow. 
     
     
       11. The micro-channel embedded heat pipe of  claim 5 , further comprising a fill tube, wherein:
 said wire-free serpentine micro-channel embedded within said planar substrate has said working fluid introduced by said fill tube positioned to allow said working fluid to be introduced into said wire-free serpentine micro-channel to partially fill said wire-free serpentine micro-channel; and 
 an unfilled region of said wire-free serpentine micro-channel is evacuated to a vacuum. 
 
     
     
       12. The micro-channel embedded heat pump of  claim 5 , wherein said planar substrate includes two metallurgically joined sheets of material. 
     
     
       13. The micro-channel embedded heat pump of  claim 5 , wherein said micro-channel includes a first plurality of micro-channel sections having a relatively larger cross-sectional area, and a second plurality of micro-channel sections having relatively small cross-sectional areas.